BACKGROUND OF STUDY Parametric Study Of Biodiesel Properties To The Storage Condition.

CHAPTER 1 INTRODUCTION

1.1 BACKGROUND OF STUDY

Biodiesel is defined as the mixture of monoalkyl esters of fatty acid methyl ester FAME such as vegetable oils, animal fats, cooking oil or algae oil which are parts of the renewable biological sources Gog et al., 2014. Sharma et al. 2008 states that renewable fuel such as biodiesel with less exhaust emissions better than petroleum diesel which is a non-renewable fuel that emit many form of pollutants and last for limited period of time. Nowadays, petroleum prices keep rising as the result of its amount continue to decrease and higher demand in industry and high usage in daily life of people around the world. Therefore, the research and development of biodiesel is being focused on the optimization of process to meet the specification and standards required for the renewable energy source or fuel to be used commercially and worldwide without decreasing or reducing the durability and efficiency of engine parts. Biodiesel is now becoming one of the alternatives to partially fulfill expected future energy demands especially in transport sector. Calero et al. 2014 states that biodiesel which is a mixture of fatty acid alkyl esters been produced by a chemical process called transesterification or alcoholysis of the parent oil or fat with an alcohol with the presence of basic catalyst usually a strong base such as sodium or potassium hydroxide. Transesterification process also producing other products which are glycerol, can also been called as glycerine with other small amount of unreacted materials, residual alcohol and residual catalyst. Basically, there are three basics paths for the biodiesel production from oils and fats which are base catalysed transesterification of the oil, direct acid catalysed transesterification of the oil and lastly, enzymatic catalysed transesterification of the oil. Base catalysts are highly sensitive to moisture and free fatty acid contents which causes a partial reaction of saponification causing the consumption of the catalyst and reduction in catalytic efficiency. Acid catalysts are used when the acid value of the feedstock is higher than the performance range of the base catalysts. Both type of catalysts have disadvantages like being energy-intensive, difficult to recover glycerol, difficulty in removal of the excess catalyst from product, treatment of alkaline waste water and interference of free fatty acids and water in the reaction Yan et al., 2014. Enzymatic transesterification on the other hand is better because of lower energy consumption, biodiesel easily separated from the reaction mixture and biodiesel purification is easier. However, in industry, base catalysts are most preferred because of the higher speed reaction, lower reaction temperature and higher conversion efficiency. The transesterification process is the reaction of a triglyceride with an alcohol and helped from catalyst to form esters and glycerine. A triglyceride has a glycerine molecule as base with three long chain fatty acids. The alcohol used is usually methanol where excess quantity of alcohol is added in the process to produce equilibrium towards the products since the process is reversible. Sufficient quantity of alcohol for the chemical reaction is 3:1 alcohol to oil molar ratio as per stoichiometry Mythili et al., 2014. The presence of catalyst aid the process because the catalyst like sodium hydroxide react with methanol to produce methoxide ion, – OCH 3 , that is required to produce the esters. The products formed are ester which is the biodiesel and glycerine, the co-product of the chemical reaction. Esters that are produced is dependent on the alcohol used using methanol will produce methyl ester and using ethanol will produce ethyl ester. However, the glycerine produced is contaminated with the unreacted material which is the glycerides, residual alcohol and residual catalyst. The following Figure 1.1 shows the transesterification process: Figure 1.1: Chemical Reaction in Producing Biodiesel Source: Gog et al., 2014 A successful transesterification reaction is determined by the separation of the biodiesel and glycerine layers after the reaction time. The glycerine produced is useful in other industry such as food industry and pharmaceutical but the contaminants need to be removed to obtain the pure glycerine and attain commercial value. In addition, automation industry especially for the diesel engine industry, the engine combustion also benefits from the good and completed process of the transesterification of the oil. The completed biodiesel must be analysed using appropriate and suitable equipment in order to ensure that it meets the specific requirements needed. The most important aspects of biodiesel production to ensure smooth and good operation in diesel engine are: 1. Complete reaction 2. Removal of glycerine 3. Removal of catalyst 4. Removal of alcohol 5. Absence of free fatty acids Comparison between biodiesel and petroleum diesel shows that biodiesel is better than the fossil fuel. First and foremost, it is a clean energy source which is environmentally friendly because of reduces in emission of carbon dioxide, sulphur dioxide and carbon monoxide Huang et al., 2012. Biodiesel has low sulphur content and contains oxygen that promotes clean burning. Biodiesel has a better flammability so that it can be transported conveniently and more safely, high viscosity which is good for lubrication to extend the life span of engine. The storage condition of the biodiesel is also important. One of the aspects that are hard to control in storage condition is temperature. Whether its the heat during day or cold during night, the change in temperature may affect the biodiesel inside the storage that possibly contribute to the degradation of biodiesel. Biodiesel has a number of standards for its quality. Most commonly standards seen are B5, B20 and B100. The “B” alphabet of the acronyms shows the percentage of biodiesel blend like B5 shows the diesel oil is 5 biodiesel and 95 petroleum diesel. Each of the standards has its own usage especially B5 which is now widely use in vehicle that use diesel engine. Based on the advantages of biodiesel and now that it is gaining global intention and market, few countries made their own biodiesel standard like European standard or European Norm EN and American Society for Testing and Materials ASTM standard. This is because vehicle manufacturers need a standard to approve vehicles to be operated using biodiesel which shows an approved biodiesel standard is important to the producers, suppliers and users. The following Table 1.1 to Table 1.3 show few standards that already exist in the world: Table 1.1: European Standard for Biodiesel EN 14214 Source: Barabas and Todorut, 2011 Propert y Test method Limits min max Unit Density at 15°C EN ISO 3675, EN ISO 12185 860 900 kgm3 Viscosity at 40°C EN ISO 3104, ISO 3105 3.5 5.0 mm2s Flash point EN ISO 3679 120 – °C Sulfur content EN ISO 20846, EN ISO 20884 – 10.0 mgkg Carbon residue in 10 dist. residue EN ISO 10370 – 0.30 mm Cetane number EN ISO 5165 5 1 – – Sulfated ash ISO 3987 – 0.02 mm Water content EN ISO 12937 – 500 mgkg Total contamination EN 12662 – 24 mgkg Copper strip corrosion 3 hours,50°C EN ISO 2160 – 1 class Oxidative stability, 110°C EN 14112 6.0 – hours Acid value EN 14104 – 0.50 mg KOHg Iodine value EN 14111 – 120 g I100 g Linolenic acid content EN 14103 – 12 mm Content of FAME with ≥4 double bonds – 1 mm Methanol content EN 14110 – 0.20 mm Monoglyceride content EN 14105 – 0.80 mm Diglyceride content EN 14105 – 0.20 mm Triglyceride content EN 14105 – 0.20 mm Free glycerine EN 14105; EN 14106 – 0.02 mm Total glycerine EN 14105 – 0.25 mm Alkali metals Na + K EN 14108; EN 14109 – 5.0 mgkg Earth alkali metals Ca + Mg EN 14538 – 5.0 mgkg Phosphorus content EN 14107 – 10.0 mgkg Table 1.2: ASTM Standard for Biodiesel ASTM D6751 Source: Alternative Fuels Data Center, 2014 Table 1.3: Comparison Between European, Germany, American and Petroleum Diesel for Biodiesel Source: Biofuel Systems, 2014 Biodiesel Standards EUROPE GERMANY USA PETROLEUM DIESEL Specification EN 14214:2003 DIN V 51606 ASTM D 6751-07b EN 590:1999 Applies to FAME FAME FAAE Diesel Density 15°C gcm³ 0.86-0.90 0.875-0.90 0.82-0.845 Viscosity 40°C mm²s 3.5-5.0 3.5-5.0 1.9-6.0 2.0-4.5 Distillation °C 90,360°C 85,350°C - 95,360°C Flashpoint Fp °C 120 min 110 min 93 min 55 min CFPP °C country specific summer 0 spraut -10 winter -20 country specific Cloud point °C report Sulphur mgkg 10 max 10 max 15 max 350 max CCR 100 mass 0.05 max 0.05 max Carbon residue 10dist.residue mass 0.3 max 0.3 max 0.3 max Sulphated ash mass 0.02 max 0.03 max 0.02 max Oxid ash mass 0.1 max Water mgkg 500 max 300 max 500 max 200 max Total contamination mgkg 24 max 20 max 24 max Cu corrosion max 3h50°C 1 1 3 1 Oxidation stability hrs;110°C 6 hours min 3 hours min NA 25 gm3 Cetane number 51 min 49 min 47 min 51 min Acid value mgKOH g 0.5 max 0.5 max 0.5 max Methanol mass 0.20 max 0.3 max 0.2 max or Fp 130°C Ester content mass 96.5 min Monoglyceride mass 0.8 max 0.8 max Diglyceride mass 0.2 max 0.4 max Triglyceride mass 0.2 max 0.4 max Free glycerol mass 0.02 max 0.02 max 0.02 max Total glycerol mass 0.25 max 0.25 max 0.24 max Iodine value 120 max 115 max Linolenic acid ME mass 12 max Cx:4 greater unsaturated esters mass 1 max Phosphorus mgkg 10 max 10 max 10 max Alkalinity mgkg 5 max Gp I metals Na,K mgkg 5 max 5 max GpII metals Ca,Mg mgkg 5 max 5 max PAHs mass 11 max Lubricity wear µm at 60°C 460 max

1.2 OBJECTIVE